Clinical Research Directory

Inclusion Criteria: * Participant aged 50 to 74. * Resident in the Île-de-France region. * Active smoker or quit smoker for 10 years or less: 1. more than 10 cigarettes a day for more than 30 years, 2. more than 15 cigarettes a day for more than 25 years. * The participant has been informed and has signed the consent form. * Social Security System affiliation. * Willingness to participate in a smoking cessation program, if currently smoking. Exclusion Criteria: * Active cancer or a history of cancer in remission for less than 5 years (except basal cell carcinoma of th skin or epithelioma in situ of the uterine cervix). * Presence of symptoms suggestive of bronchopulmonary cancer. Participants with these symptoms require immediate diagnostic investigations and are therefore not eligible for screening. * Weight \>= 140 kg. * Severe comorbidity contraindicating therapeutic options or invasive thoracic diagnostic investigations. * Inability to climb two flights of stairs without stopping. * A thoracic CTscan performed within the previous year. * Persons deprived of liberty or under guardianship. * Impossibility to undergo the medical monitoring of the trial for geographical, social or psychological reasons.